class MyStack:
def __init__(self):
self.q = deque()
def push(self, x: int) -> None:
self.q.append(x)
for _ in range(len(self.q) - 1):
self.q.append(self.q.popleft())
def pop(self) -> int:
return self.q.popleft()
def top(self) -> int:
return self.q[0]
def empty(self) -> bool:
return len(self.q) == 0